Size and Shape of a Bubble on the Upper Surface of a Horizontal Plate of Poor Wettability

Abstract

Air was gradually supplied through a small vertical hole to form a single bubble on the upper surface of a horizontal flat plate of poor wettability. The bubble grew with an increase in the supplied air volume. The growing behavior of the bubble was observed with a CCD camera. The shape and size of the bubble on the upper surface of the plate were determined as functions of the surface tension, contact angle, densities of liquid and gas based on an energy equation for the bubble. Furthermore, the maximum bubble volume which allows a bubble to stay on the upper surface of the plate was predictable from the energy equation and a force balance equation for the bubble.